Container



1961 J. G. SHAKMAN 2,971,671

CONTAINER Filed Oct. a1, 1956 INVENTOR: JAMES G. S AKMAN BY 4.

ATT'YS United States PatentO CONTAINER James G. Shakman, Wilmette, IIL, assignor to Pabst Brewing Company, Milwaukee, Wis., a corporation of Delaware Filed Oct. 31, 1956, Ser. No. 619,51?

2 Claims. (Cl. 220-66) This invention relates to a new and improved type of container and more particularly to a new and improved type of can adapted to be used for canning substances which are under pressure or develop internal pressure in the can.

One of the objects of the invention is to provide a new and improved container-type of structure which is adapted to relieve internal pressures and to provide a margin of safety as compared with conventional cans.

A further object of the invention is to provide a container having end closures, portions of which are adapted to move from one position to another to relieve internal pressure in the container.

Another object of the invention is to provide a container which is especially adapted for canning carbonated beverages, including beer and ale, as well as soft drinks.

An additional object of the invention is to provide a container of the type described which is capable of changing shape during processing of a substance sealed therein.

Still a further object of the invention is to provide a container which can be used for canning carbonated liquids such as beer and other carbonated beverages and is capable of altering its shape to provide increased headspace above the liquid level after the beverage has been sealed in the container.

Another object of the invention is to provide containers of the type described which are capable of being stacked one on top of the other.

Other objects and advantages of the invention will appear from the following description in conjunction with the following drawing in which:

Fig. l is an exploded elevational view of a can of a type suitable for use in the practice of the invention;

Fig. 2 is a vertical cross sectional view of said can after it has been filled with liquid and sealed;

Fig. 3 is a vertical cross section of the filled can of Fig. 2 after the end closures thereof have flexed from a concave shape to a convex shape; and

Fig. 4 is an enlarged cross sectional view of a portion of the filled can shown in Figs. 2 and 3 illustrating the change which occurs in the end closures of the can under the influence of internal pressure generated within the can.

In accordance with the invention a container is provided having a body portion which is referably cylindrical and top and bottom closures characterized by the fact that the top and bottom closures are recessed or countersunk and have concave reentrant portions which are capable of flexing outwardly under internal pressure developed by the material in the container after sealing to produce convex portions but at the same time do not extend beyond the rim of the recesses or countersunk portions at the top and bottom of the container. Thus, a can is filled as shown in Fig. 2 and processed, for example, by heating it or otherwise processing it so that the material within the can develops an internal pressure. The concave end closures are then forced outwardly until they assume a convex shape as shown in Fig. 3, thereby providing additional head space at the top of the filled "ice can but without interfering with the stacking properties.

In the desired structure illustrated in the drawings the can comprises a cylindrical body portion 1 initially provided with flange portions 1a and 1b as shown in Fig. 1, a top closure 2 and a bottom closure 3. The top closure 2 has a recessed or countersunk portion 4.

As shown in Fig. 2 the upper closure member 2 has a concave portion 6 and the lower closure member 3 has a concave portion 7. In the particular embodiment shown there are annular recesses 8 and 9 within the larger recesses or countersunk portions 4 and 5, respectively. The end closure 3 is sealed to the bottom of the can in a conventional manner, for example, by double seaming, whereby the flange 1b is interlocked with the rim of end closure 3 as shown at 12. The material to be canned 10 is then placed within the can and the end closure 2 is similarly sealed to the top of the can by double seaming the rim of the end closure 2 and the flange 1a of the cylindrical body as shown at 11. The cylindrical body portion 1 can have a side seam or it can be seamless as shown in Fig. 1.

The structure of the end closures 2 and 3 is such that the concave parts 6 and 7 are adapted to flex or pop out and assume a convex position as shown in Fig. 3. It will be observed that the outermost parts of the convex portion in each case is within the confines or countersunk portions 4 and 5. It Will also be observed that when this inversion of the end portions 6 and 7 occurs, it produces 'an enlarged head space as shown at 16.

By initially using a container or can having concave end closures as shown in Fig. 2 it is unnecessary to provide a maximum amount of head space when the can is filled and therefore smaller cans can be used to contain the same volume of liquid and still provide the desired head space after the can has been sealed. I

Containers or cans of the type herein described are preferably formed of sheet metal such as sheet steel or aluminum but it will be understood that the term can is used herein in a general sense and is not limited to a metal can. The principles of the invention are applicable to the use of cans constructed of various types of materials including plastic materials of suflicient flexibility and rigidity to accomplish the desired result.

The thickness of the sheet material used in forming the can may vary depending upon the type of material employed, the only requirement being that the material should be rigid enough to maintain its shape but the end closure portions 6 and 7 should be flexible enough to change from a concave shape to a convex shape under the influence of the pressure generated in the can. The material used in forming the can may be of the same thickness throughout but in some cases it may be desirable that the end closures be thicker than the side closures of the can. For example, in a beer can made of sheet steel or sheet aluminum the lids or end closures can be 12 mils thick and the body 10 mils thick.

It will be understood that the bottom of the container can be integral with the tubular body as in a stamping or extrusion so long as it conforms to the shape previously described.

Containers of the type herein described can be employed for canning beer, ale and other carbonated bev-' erages, including soft drinks. They can also be employed in the canning of tomato juice, corn, vegetables, and the like. Furthermore, they can be used in canning coffee and other solid materials which are canned in the presence of inert gases such as nitrogen or generate gases after being sealed in the can.

As an example of the use of a can of the type herein described, beer is placed in a can as shown in Fig. 2, the can is sealed and is then heated in a pasteurizing step at a temperature around F. thereby producing internal expansion of carbon dioxide which causes the end closure portions 6 and 7 to assume the convex shape shown in Fig. 3 and at the same time produce the head space 16. In using cans of the invention in the manner just described it is usually preferable to till the can to the point where the innermost part 13 of the concave end closure '6 will be closely adjacent to the liquid level 14 as shown in Fig. 4, leaving the space 15 unfilled. Thereafter, when the can is processed, for example, by heating, the internal pressure is sufiicient to cause the end closure 6 to move outwardly to the dotted line position and provide a much larger head space.

While the body portion 1 has been shown as being cylindrical it should be understood that it is not absolutely essential to have a circular cross section because other cross sectional shapes such as triangular and rectangular can be used without departing from the invention. The word tubular as used herein contemplates the employment of any such cross sections.

The fact that the end closures 6 and 7 are adapted to flex and change shape from a concave shape to a convex shape reduces internal pressure and relieves the strain on the can. Heretofore many cans have been constructed with reenforcing grooves in the end closures which are placed there for the purpose of increasing the rigidity and function to substantially prevent outward expansion. Cans of this type with or without side seams in the body must be fabricated with larger capacity thus containing more material so that when under maximum pressure the shape will not be distorted by the internal pressure. The present invention makes it possible to provide proper head space and utilize a minimum amount of material and at the same time provide cans which are capable of being stacked one on top of the other. Since the invention makes it possible to use smaller cans, such cans can be manufactured out of the most desirable materials in any situation, such as aluminum, with a minimum increase in the cost.

The invention is hereby claimed as follows: r

1. A can comprising a tubular body portion, and en closures mounted on said body portion, said end closures being recessed, and each of said closures comprising a continuous outer rim, a normally continuously inwardly concave central portion extending substantially across said end closure and adapted to hex outwardly to form predetermined continuously convex shapes within the confines of said recess of said closure under the influence of internal pressure within the can, said central portion having a continuous outer edge normally disposed outwardly, longitudinally of said body portion, of the other portions of said closure disposed within said rim.

2. A can for carbonated beverages comprising a tubular body portion, and end closures mounted on said body portion, said end closures being recessed, and each of said end closures comprising a continuous outer rim, a normally continuously inwardly concave central portion extending substantially across said end closure, and a continuous inwardly concave other portion extending around said central portion and directly connected at one edge to said central portion and at another edge to said outer edge, said one rim being normally disposed outwardly, longitudinally of said body portion, of the other portions of said closure disposed within said outer rim, said central portion being flexible into a continuously convex shape within the confines of said recess of said closure and outwardly, longitudinally of said body portion, of said one edge under the influence of internal pres sure within the can.

References Cited in the file of this patent UNITED STATES PATENTS 1,570,732 Emerson Jan. 26, 1926 1,913,652 Alexander June 13, 1933 2,012,213 Young Aug. 20, 1935 2,027,430 Hansen Jan. 14, 1936 UNITED STATES PATENT OFFICE CERTIFICATION OF CORRECTION Patent No. 2,971,671 February 14,, 1961 James G; Shakman It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read'as corrected below.

Column 4, line 23 1 for "edge, said one rim" read rim said one edge Signed and sealed this 15th day of August 1961t (SEAL) I Attest:

ERNEST W. SWIDER DAVID L. LADD Attesting Officer Commissioner of Patents 

